Bellhousing bolts coming loose.

[shackwrrr]

How does e eryone else keep these damn things in. I blue locktited mine in and I've driven my van 4 days, and the two top ones were nearly all the way out all the lowers were loose. The two in the front of the block for the front mount were loose too. The big 18mm heads are a real pain. To drill for safety wire. This is on a non balance shaft 2.5 but the bottom end has been balanced.

[speedfreek500]

I use blue locktight also, But befoe i use it i wire wheel the bolts and clean the threads really good with brake clean. I have never had one come loose on its own preping the bolt and block that way.

[cordes]

IIRC the torque spec for them is 70ft/lbs. What are you torquing them to? Do you have the dowels in the ears of the block? I've read that if those aren't present it can cause the bolts to walk.

[GLHNSLHT2]

are you using the factory bolts with the serated faces on them to keep them tight?

[shackwrrr]

are you using the factory bolts with the serated faces on them to keep them tight?

At the lower 4 holes. The top 2 are 18mm head with washer. I've never seen the serrated ones in the top hole.

[shackwrrr]

I'm making them as tight as I can get them with a 12 in ratchet much tighter than 70. I did brake keen the bolt holes and the bolts were sonic cleaned so they were dry.

[cordes]

It sounds like you've got everything in the right spot, but to double check, you do have the really long ones in the proper places correct?

[dixiedodge7369]

Did you try red lock tight? I don't ever bother with blue...

[shackwrrr]

Yes, I used 4 of the 15mm headed serrated long ones in all bolts screwing into the aluminum. The 2 top bolts are long enough to catch all the threads.

[cordes]

Yes, I used 4 of the 15mm headed serrated long ones in all bolts screwing into the aluminum. The 2 top bolts are long enough to catch all the threads.

All trans to block bolts should be 18mm heads from the factory.

[shackwrrr]

I don't know where they came from, I had a few from my spirit, and other Turbo mopars that I've disassembled. I just know they make it a lot easier to tighten the hard to get to bolts. The serrated head should help but they still come loose.

[cordes]

I don't know where they came from, I had a few from my spirit, and other Turbo mopars that I've disassembled. I just know they make it a lot easier to tighten the hard to get to bolts. The serrated head should help but they still come loose.

I've never pulled a 15mm headed trans to block bolt out of any FWD chrysler I've come across. Even the front motor mount to block bolts have all been 18mm heads. Perhaps you could try some of the standard ones?

[RoadWarrior222]

The 15mm ones like to turn up on starters for some reason.

Got no tips for you, I bolt mine up, they stay bolted up :shrug:

[shackwrrr]

Ill have to get a picture. They have the same rating of the other bolts 10.9 I think. Ive pulled them all out of bellhousings. Maybe newer cars?

[black86glhs]

Maybe you just have the right resonance on your setup that is causes them to vibe out. That is the best I can come up with. I'm with RW222....I have never had one loosen up on anything I've worked on. Weird....:(

[shackwrrr]

weird, My old 2.5 that was in my shadow did the same thing. Must just be how I drive, I guess Ill have to drill them for safety wire.

[cordes]

The 15mm ones like to turn up on starters for some reason.

Got no tips for you, I bolt mine up, they stay bolted up :shrug:

And they are a size down from the trans to block bolts. I have accidentally put a couple of those in by mistake back when I first got in to these cars. I highly doubt the OP has done this as it is a super duper rookie mistake that I doubt he would make.

[supercrackerbox]

I've had a lot of problems with the ones on the front engine mount come loose from both the bellhousing and block, on several cars. Try finding a small brush to scrub the threads clean in the bellhousing, flush with more brake cleaner, and blow them out with compressed air if available. Brake cleaner can actually stay wet in the holes for a long while if there's no airflow to evaporate it. Try the blue locktite again. If they come loose again, find new bolts.


I've never pulled a 15mm headed trans to block bolt out of any FWD chrysler I've come across. Even the front motor mount to block bolts have all been 18mm heads. Perhaps you could try some of the standard ones?

I've seen a lot of the '90ish and up cars having 15mm heads on the two bolts that hold the front engine mount bracket to the bellhousing. They also had serrated flanges as mentioned above. But given all the inconsistencies we've found with these cars, I certainly wouldn't say they all had them.

[cordes]

They probably had the serrated flanges due to all of them walking out. The bottom one on the front motor mount is the one I've always had trouble with. I'll be running a long bolt through and nutting it on the back side the next time I do one.

[Reaper1]

I've had them come loose on my car as well. Red Loc-Tite and the correct torque...no more issues!

[turbovanman²]

As said, the 2 lower ones are 15mm serrated, my van has those, maybe its a CB thing?

I've never had any come loose over the years but the one car I fixed that did, the dowel pins weren't there.

[GLHS069]

My 86 GLHS has the 15mm bolts on the bottom 2 too, so it's not a CB thing.
And Cordes, I did the same thing on my front bolt with the nut on the back side.

[shackwrrr]

Mine has the dowels. I'll try cleaning the holes again.

[Mech Dude]

Hey I know this might be late but... I'm pretty sure your loose bolt problem are due to clutch chatter. Hopefully you guys know what that means! I'll attack a photo with proof and link.

https://goo.gl/photos/KyA9didaoTXVGTY46

https://goo.gl/photos/KyA9didaoTXVGTY46

[c2xejk]

The case I have heard of where the engine to tranny bolts where coming loose, the bell-housing was cracked. Under normal driving the crack would open up a little and allow the bolt to start backing out... I doubt even loc-tite would fix that... I think the temporary fix was to get longer bolts and put nuts on them...

[shackwrrr]

It has been fine for a while now. The clutch is a very chattery sintered iron unsprung unit. I switched out most of the bolts to the 15mm head bolts with the serrated flanges and that seems to have fixed it. Going on 5 years now.

[ShadowFromHell]

Old thread but will still add this...

I haven't seen it in TM's but have seen this in a couple neons. No matter what the bolts come loose. New bolts, hardware store bolts at that and no more issues. The conclusion we came to is that they were stretching like a bad head bolt and wouldn't hold the TQ. This was on a car that had many, many motor/tranny/clutch swaps. Couldn't tell you how many times the car had been apart. I thought my buddy was out of his mind when he said he was going to get new bolts because he had been told that was the problem. But it fixed it.